Rosman said he used hybrids in the past and started to use GMO corn in feed in 1997 without any trouble, but things changed in 2000 when he switched to a different company’s genetics with a new genetically modified trait.

Starting in 2000, most of Rosman’s animal were unable to reproduce with a low sperm count in males and females showing false pregnancies. The pigs that were reproducing had smaller litters. By adjusting the type of corn used, Rosman concluded the corn with the genetically modified trait he started using in 2000 was causing the problem. Continued losses and his shrinking herd forced him to close his farm two years later.

A 2006 publication from the International Service for the Acquisition of Agri-Biotech Applications (ISAAA) reports at least 65 million metric tons of GM corn grains are used in livestock diets annually and extensive testing and a long approval process accompany every GM crop introduction.

The resource explains safety concerns on the use of GM crops as feed ingredients involve three questions:

Are GM crops safe as feeds for livestock?

Is animal performance affected by GM crops?

Could transgenic materials be transferred to and accumulate in milk, meat, and eggs?

“Feeding trials have been conducted to examine the safety and efficacy of GM feeds for farm livestocks. Based on these studies, there is no evidence of significantly altered nutritional composition, deleterious effects, or the occurrence of transgenic DNA or protein in animal products derived from animals fed with GM feed ingredients.”

Additionally, a study by University of Nebraska researchers found no difference between cattle grazing genetically enhanced corn hybrids and their non-genetically enhanced parent hybrid.